Drug interactions
Oxybutynin + Promazine
Severity: Moderate
Oxybutynin and Promazine: moderate interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Promazine is a phenothiazine with notable anticholinergic activity, so combining it with oxybutynin adds to antimuscarinic burden. This can cause dry mouth, constipation, urinary retention, blurred vision, tachycardia and confusion, especially in older adults.
What this interaction means in plain words
Oxybutynin and Promazine can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Why it happens
Additive anticholinergic (antimuscarinic) pharmacodynamic effects.
What to do
Monitor for anticholinergic adverse effects and cognitive changes, and reduce the dose or choose a less anticholinergic alternative if they develop.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Oxybutynin
Frequently asked questions
Can I take Oxybutynin with Promazine?
MediHelp rates the interaction as moderate. Oxybutynin and Promazine can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Promazine is a phenothiazine with notable anticholinergic activity, so combining it with oxybutynin adds to antimuscarinic burden. This can cause dry mouth, constipation, urinary retention, blurred vision, tachycardia and confusion, especially in older adults.
How serious is the interaction between Oxybutynin and Promazine?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor for anticholinergic adverse effects and cognitive changes, and reduce the dose or choose a less anticholinergic alternative if they develop.
What other medicines interact with Oxybutynin?
MediHelp also lists interactions of Oxybutynin with, for example, Bethanechol, Clozapine, Potassium chloride. The full list is on the Oxybutynin page.
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